In most episodes of low back pain, a specific underlying cause is not identified or even looked for, with the pain believed to be due to mechanical problems such as muscle or joint strain.[1][4] If the pain does not go away with conservative treatment or if it is accompanied by "red flags" such as unexplained weight loss, fever, or significant problems with feeling or movement, further testing may be needed to look for a serious underlying problem.[5] In most cases, imaging tools such as X-ray computed tomography are not useful and carry their own risks.[9][10] Despite this, the use of imaging in low back pain has increased.[11] Some low back pain is caused by damaged intervertebral discs, and the straight leg raise test is useful to identify this cause.[5] In those with chronic pain, the pain processing system may malfunction, causing large amounts of pain in response to non-serious events.[12]
Take nonprescription pain medicine, such as acetaminophen, ibuprofen, or naproxen. Read the label and take as directed. Nonsteroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen or naproxen, may cause stomach bleeding and other problems. These risks increase with age. Unless recommended by your healthcare provider, do not take an NSAID for more than 10 days.
Premkumar et al present evidence that the traditional “red flags” for ominous causes of back pain can be quite misleading. The correlation between red flags and ominous diagnoses is poor, and prone to producing false negatives: that is, no red flags even when there is something more serious than unexplained pain going on. In a survey of almost 10,000 patients “the absence of red flag responses did not meaningfully decrease the likelihood of a red flag diagnosis.“ This is not even remotely a surprise to anyone who paid attention in back pain school, but it’s good to have some harder data on it.

The lumbar (or lower back) region is made up of five vertebrae (L1–L5), sometimes including the sacrum. In between these vertebrae are fibrocartilaginous discs, which act as cushions, preventing the vertebrae from rubbing together while at the same time protecting the spinal cord. Nerves come from and go to the spinal cord through specific openings between the vertebrae, providing the skin with sensations and messages to muscles. Stability of the spine is provided by the ligaments and muscles of the back and abdomen. Small joints called facet joints limit and direct the motion of the spine.[30]
Iliopsoas syndrome, which is also called psoas syndrome or iliopsoas tendonitis, occurs when the iliopsoas muscles are injured. Lower back pain is the most common symptom; however, pain can also occur in the hip, thigh, or leg. The iliopsoas bursa, which is a fluid-filled sac located on the inside of the hip that reduces rubbing and friction, is also likely to become inflamed due to the proximity of the two structures. When this happens, the inflamed bursae will make it difficult to move.
Sciatica is a form of radiculopathy caused by compression of the sciatic nerve, the large nerve that travels through the buttocks and extends down the back of the leg. This compression causes shock-like or burning low back pain combined with pain through the buttocks and down one leg, occasionally reaching the foot. In the most extreme cases, when the nerve is pinched between the disc and the adjacent bone, the symptoms may involve not only pain, but numbness and muscle weakness in the leg because of interrupted nerve signaling. The condition may also be caused by a tumor or cyst that presses on the sciatic nerve or its roots.
To avoid hip flexor pain, you should pay more attention to these muscles, Dr. Siegrist explains. When you are seated, your knees are bent and your hip muscles are flexed and often tighten up or become shortened. “Because we spend so much of our time in a seated position with the hip flexed, the hip flexor has the potential to shorten up. Then, when you are in a hurry because you are running to catch a bus or a plane, or you trip and fall, the muscle could become stretched. Here’s this stiff, brittle muscle that all of a sudden gets extended, and you could set yourself up for strain or some hip flexor pain.” Click Here to Learn Unlock Hip Flexors